This seems similar to bug 616709 (https://bugzilla.gnome.org/show_bug.cgi?id=616709). However, I decided to submit this anyway just in case my bug does not have the same root cause as bug #616709.

Reproducing the bug:
Open your favorite GnuCash file (for me, that is personal.gnucash).
Be sure you are in the default view (the Accounts tab) of GnuCash.
Be sure to enable the "Description" column.
Click any account to select it.
Now click on the account's Description. This should highlight the description and allow you to edit it.
If you try to delete any characters in the description of this account, GnuCash will offer to DELETE YOUR ACCOUNT.

This is obviously a bug, because the user is most likely pressing the delete key to edit the Description text of the account.

I'm running Windows 7 Ultimate 64 bit.
My gnucash help->about:
GnuCash 2.6.18
The GnuCash personal finance manager. The GNU way to manage your money!
This copy was built from git rev 3a9fbb8+ on 2017-09-25.
© 1997-2017 Contributors

Thank you very much, developers!
I seriously love this program.
I'm very grateful that there are people who enjoy creating solid software. People with integrity who seek to program things the right/best way, even when it isn't the easiest or fastest to achieve.

Ryan